Daniel Darvas

Daniel Darvas
European Organization for Nuclear Research | CERN · Beams Department (BE)

PhD

About

31
Publications
7,950
Reads
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383
Citations
Additional affiliations
June 2017 - present
European Organization for Nuclear Research
Position
  • Fellow
September 2014 - May 2017
Budapest University of Technology and Economics
Position
  • PhD Student
Description
  • I was working on formal specification methods for PLC software. Secondarily, I was developing saturation-based model checking methods (mainly for bounded model checking).
September 2014 - May 2017
European Organization for Nuclear Research
Position
  • PhD Student
Description
  • I was working on new lightweight, formal specification methods for PLC-based control software development.
Education
February 2012 - June 2014
Budapest University of Technology and Economics
Field of study
  • Computer Engineering

Publications

Publications (31)
Article
Full-text available
Since their invention, Petri nets have provided modelling and analysis methods to support the design of correct, reliable and robust systems. This motivated our work to develop PetriDotNet, a Petri net editor and analysis tool. In this paper we overview the supported modelling formalisms and the analysis methods included in PetriDotNet. Next, we pr...
Thesis
Formal specification and verification methods provide ways to describe requirements precisely and to check whether the requirements are satisfied by the design or the implementation. In other words, they can prevent development faults and therefore improve the quality of the developed systems. These methods are part of the state-of-the-practice in...
Article
Programmable logic controllers are typically programmed in one of the five languages defined in the IEC 61131 standard. While the ability to choose the appropriate language for each program unit may be an advantage for the developers, it poses a serious challenge to verification methods. In this paper we analyse and compare these languages to show...
Conference Paper
The complexity and quality needs of PLC-based control system software have largely increased. Formal specification methods can help to cope with these needs. Besides formal verification, another benefit of a formal specification language is the possibility to provide automatic generation of the final source code. This paper overviews PLCspecif, our...
Conference Paper
PetriDotNet is an extensible Petri net editor and analysis tool originally developed to support the education of formal methods. The ease of use and simple extensibility fostered more and more algorithmic developments. Thanks to the continuous interest of developers (especially M.Sc. and Ph.D. students who choose PetriDotNet as the framework of the...
Conference Paper
Programmable Logic Controllers (PLCs) are widely used in the industry for various industrial automation tasks. Besides non-safety applications, the usage of PLCs became accepted in safety-critical installations, where the cost of failure is high. In these cases the used hardware is special (so-called fail-safe or safety PLCs), but also the software...
Article
Efficient symbolic and explicit-state model checking approaches have been developed for the verification of linear time temporal logic (LTL) properties. Several attempts have been made to combine the advantages of the various algorithms. Model checking LTL properties usually poses two challenges: one must compute the synchronous product of the stat...
Article
Full-text available
Formal verification is becoming a fundamental step in assuring the correctness of safety-critical systems. Since these systems are often asynchronous and even distributed, their verification requires methods that can deal with huge or even infinite state spaces. Model checking is one of the current techniques to analyse the behaviour of systems, as...
Article
Full-text available
Programmable Logic Controllers (PLCs) are embedded computers widely used in industrial control systems. Ensuring that a PLC software complies with its specification is a challenging task. Formal verification has become a recommended practice to ensure the correctness of safety-critical software but is still underused in industry due to the complexi...
Conference Paper
Full-text available
Model checking is a promising formal verification method to complement testing in order to improve the quality of PLC programs. However, its application typically needs deep expertise in formal methods. To overcome this problem, we introduce PLCverif, a tool that builds on our verification methodology and hides all the formal verification-related d...
Conference Paper
Full-text available
The correctness of the software used in control systems has been always a high priority, as a failure can cause serious expenses, injuries or loss of reputation. To improve the quality of these applications, various development and verification methods exist. All of them necessitate a deep understanding of the requirements which can be achieved by...
Conference Paper
Full-text available
Efficient symbolic and explicit model checking approaches have been developed for the verification of linear time temporal properties. Nowadays, advances resulted in the combination of on-the-fly search with symbolic encoding in a hybrid solution providing many results by now. In this work, we propose a new hybrid approach that leverages the so-cal...
Conference Paper
One of the main obstacle that prevents model checking from being widely used in industrial control systems is the complexity of building formal models out of PLC programs, especially when timing aspects need to be integrated. This paper brings an answer to this obstacle by proposing a methodology to model and verify timing aspects of PLC programs....
Conference Paper
Full-text available
Formal verification has become a recommended practice in the safety-critical application areas. However, due to the complexity of practical control and safety systems, the state space explosion often prevents the use of formal analysis. In this paper we extend our former verification methodology with effective property preserving reduction techniqu...
Conference Paper
Verification of critical software is a high priority but a challenging task for industrial control systems. Model checking appears to be an appropriate approach for this purpose. However, this technique is not widely used in industry yet, due to some obstacles. The main obstacles encountered when trying to apply formal verification techniques at in...
Article
Full-text available
The failure of safety-critical embedded systems may have catastrophic consequences, therefore their development process requires a strong verification procedure to obtain a high confidence of correctness in the specification and implementation. Formal modelling and model checking provides a rigorous, mathematically precise verification method. Prac...
Conference Paper
Full-text available
Formal verification is becoming a fundamental step in assuring the correctness of safety-critical systems. Since these systems are often asynchronous and even distributed, their verification necessitates methods that can deal with huge or even infinite state spaces. Model checking is one of the current techniques to analyse the behaviour of systems...
Article
Formal verification is becoming a fundamental step of safety-critical and model-based software development. As part of the verification process, model checking is one of the current advanced techniques to analyse the behaviour of a system. Symbolic model checking is an efficient approach to handling even complex models with huge state spaces. Satur...
Conference Paper
Full-text available
The verification of embedded, safety-critical industrial systems is important, since a failure of these systems may have catastrophic consequences. Formal methods guarantee not only the correctness, but also the completeness of the analysis. However, even moderately complex industrial systems have state spaces so large that former analysis techniqu...
Conference Paper
Full-text available
Nowadays the formal verification of software and hardware systems is gaining an even more important role in system design. As the size of the systems grows, their verification becomes an increasingly complex task. This creates many new requirements for verification tools, also for model checking tools. In my work I have investigated the so-called b...
Conference Paper
Full-text available
Formal verification is becoming a fundamental step of safety-critical and model-based software development. As part of the verification process, model checking is one of the current advanced techniques to analyse the behaviour of a system. In this paper, we examine how the combination of two advanced model checking algorithms - namely bounded satur...
Conference Paper
Full-text available
Formal verification is becoming a fundamental step of safety-critical and model-based software development. As part of the verification process, model checking is one of the current advanced techniques to analyze the behavior of a system. In this paper, we examine an existing parallel model checking algorithm and we propose improvements to eliminat...

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